In communications networks, there may be a challenge to obtain good performance and capacity for a given communications protocol, its parameters and the physical environment in which the communications network is deployed.
For example, for future generations of mobile communications networks, frequency bands at many different carrier frequencies could be needed. For example, low such frequency bands could be needed to achieve sufficient network coverage for terminal devices and higher frequency bands (e.g. at millimeter wavelengths (mmW), i.e. near and above 30 GHz) could be needed to reach required network capacity. In general terms, at high frequencies the propagation properties of the radio channel are more challenging and beamforming both at the network node of the network and at the terminal devices might be required to reach a sufficient link budget.
In a communications network where a transmission and reception point (TRP) at the network side uses narrow beams for transmission, at least one of the narrow transmission beams is assumed to be discovered and monitored for each served terminal device at the user side. This process of discovering and monitoring is referred to as beam management. In order to perform beam management the network node uses measurements (such as received reference signal power), as obtained and reported by the served terminal devices, on downlink reference signals such as channel state information reference signals (CSI-RS). The beam pair for which the highest received reference signal power was obtained is then used as the active beam pair link.
In general terms, a beam pair is defined by a transmission beam at the transmitting end (such as at the TRP) and a corresponding reception beam at the receiving end (such as at the terminal device), where the transmission beam and the reception beam are selected from sets of available candidate beams so as to maximize a quality criterion (such as highest received reference signal power) for transmission from the transmitting end to the receiving end.
The CSI-RS for beam management might be transmitted periodically, semi-persistently or aperiodically (for example when being event triggered) and they might either be shared between multiple terminal devices or be specific for a certain terminal device, or group of terminal devices. It is desirable to have as few always-on signals as possible in the communications network in order to reduce the power consumption and generated interference. Hence, aperiodically event triggered beam management might be preferred in many cases. Still, beam management might require large overhead signaling and be time consumption, especially for analog and hybrid antenna array implementations at the TRP where beams must be swept in a sequential manner.
Hence, there is still a need for an improved beam management of radio transceiver devices, such as beam management of terminal devices and network nodes.